You and I play a game involving successive throws of a fair coin.
Suppose I pick HH and you pick TH. The coin is thrown repeatedly
until we see either two heads in a row (I win) or a tail followed
by a head (you win). What is the probability that you win?

A gambler bets half the money in his pocket on the toss of a coin,
winning an equal amount for a head and losing his money if the
result is a tail. After 2n plays he has won exactly n times. Has he
more money than he started with?

Dice & Spinners Interactive

Here you can simulate throwing a dice and spinning a spinner.

To throw a dice, click on 'Dice' then click
'Play'.
You can have more than one dice by clicking 'Dice' again.

To use a spinner, first choose how many numbers it will have by
clicking on the + and - signs.
Then click on the spinner to select it.
Again, you can have more than one spinner.
Click 'Play' to spin the spinner/s.

Once you have selected a spinner, you can edit the numbers, for
example you may want to include a zero. Click 'Edit'
and enter your chosen numbers in the boxes.

The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the
NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to
embed rich mathematical tasks into everyday classroom practice. More information on many of our other activities
can be found here.